Interpretations of Biological Communities Based on Analysis of Geologic and Manned Submersible Records

A biological and geological reconnaissance survey was conducted at Tanner and Cortes Banks located offshore from San Diego, California. Bathymetric and side scan data were collected using standard methods and converted to bathymetric base maps with overlays of the sea floor geomorphology. Biological data were collected by scientists using the manned submersible NEKTON to record species abundances along 56 nmi of transects. Dominant species assemblages were plotted along transect lines superimposed on maps of bathymetry and geomorphology. Biological communities were interpolated between submersible tracklines using geological data and knowledge of the relationship between organisms, substrate and depth. The analysis was facilitated by the close coordination of data collection times with precise navigational positions. This method is broadly applicable to analysis of biological communities, particularly large-scale baseline studies conducted in areas of rocky substrate.